perhaps on the control column? not sure will have a little root around when flying tommorrow.
If you feel up to it you can ask him to find the letter J anywhere in the flight deck not counting the CDU!!
There are only 2 and they're a bugger to find. a hint have a close look at the handle to move the rudder peddles.
Don't help him and just watch him stare at all the bulbs with the light test on.
And yes i did it too.